Reviewers: ,
Message:
The idea here is to create a generic framework that allows for
modifications to note lengths (i.e. swing) in the MIDI without having a
typographical impact on the score.

Brilliant idea, from my rather amatheurish point of view!
Regards,
Marc

I nixed the patch because Xavier informed me that one could just
create two separate score blocks, one for layout and one for midi.
This makes it possible to feed different music to the two blocks,
which solves the problem, so it's not necessary to touch the C++
code.

No, no! It would be great to use one input for graphical *and* midi
output by just applying a suitable make-swing-formatter, written in
scheme.

Nobody keeps you from writing
\midi { \makeSwingFormatter \music }

I tried to write such stuff long ago, but I was told that it is not
possible to

get the informations about beats and measures within such a scheme function.
Mike's proposal opened a way to get exactly this information.

and it has the advantage that you can use
\score { \makeSwingFormatter \music }
for a much easier check that the swing formatter is doing what you
want if the swing formatter works by altering _main_ durations. And if
the swing formatter works by altering _factors_, you will want it not as
much for proofreading, but for actual typesetting since it will then
"swing" the note placement.

I think this patch would make life much easier! Writing every pairs
of eights as triplets again and again is so annoying ...

Huh? Mike did not suggest that you create the swinged version manually.

Oh, come on - if I were to write music containing just pairs of eights,
I would not have complained about the withdrawing of the patch ;-)
Furthermore, a built-in solution is better than a half-brewn python script
parsing my lilypond data (which I even did not write yet).
Regards,
Marc